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linux/drivers/w1/slaves/w1_ds2433.c
Andrew F. Davis de0d6dbdbd w1: Add subsystem kernel public interface 
Like other subsystems we should be able to define slave devices outside
of the w1 directory. To do this we move public facing interface
definitions to include/linux/w1.h and rename the internal definition
file to w1_internal.h.

As w1_family.h and w1_int.h contained almost entirely public
driver interface definitions we simply removed these files and
moved the remaining definitions into w1_internal.h.

With this we can now start to move slave devices out of w1/slaves and
into the subsystem based on the function they implement, again like
other drivers.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:54:54 +02:00

309 lines
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/*
* w1_ds2433.c - w1 family 23 (DS2433) driver
*
* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
#include <linux/crc16.h>
#define CRC16_INIT 0
#define CRC16_VALID 0xb001
#endif
#include <linux/w1.h>
#define W1_EEPROM_DS2433 0x23
#define W1_EEPROM_SIZE 512
#define W1_PAGE_COUNT 16
#define W1_PAGE_SIZE 32
#define W1_PAGE_BITS 5
#define W1_PAGE_MASK 0x1F
#define W1_F23_TIME 300
#define W1_F23_READ_EEPROM 0xF0
#define W1_F23_WRITE_SCRATCH 0x0F
#define W1_F23_READ_SCRATCH 0xAA
#define W1_F23_COPY_SCRATCH 0x55
struct w1_f23_data {
u8 memory[W1_EEPROM_SIZE];
u32 validcrc;
};
/**
* Check the file size bounds and adjusts count as needed.
* This would not be needed if the file size didn't reset to 0 after a write.
*/
static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size)
{
if (off > size)
return 0;
if ((off + count) > size)
return (size - off);
return count;
}
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
int block)
{
u8 wrbuf[3];
int off = block * W1_PAGE_SIZE;
if (data->validcrc & (1 << block))
return 0;
if (w1_reset_select_slave(sl)) {
data->validcrc = 0;
return -EIO;
}
wrbuf[0] = W1_F23_READ_EEPROM;
wrbuf[1] = off & 0xff;
wrbuf[2] = off >> 8;
w1_write_block(sl->master, wrbuf, 3);
w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
/* cache the block if the CRC is valid */
if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
data->validcrc |= (1 << block);
return 0;
}
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
struct w1_f23_data *data = sl->family_data;
int i, min_page, max_page;
#else
u8 wrbuf[3];
#endif
if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
return 0;
mutex_lock(&sl->master->bus_mutex);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
min_page = (off >> W1_PAGE_BITS);
max_page = (off + count - 1) >> W1_PAGE_BITS;
for (i = min_page; i <= max_page; i++) {
if (w1_f23_refresh_block(sl, data, i)) {
count = -EIO;
goto out_up;
}
}
memcpy(buf, &data->memory[off], count);
#else /* CONFIG_W1_SLAVE_DS2433_CRC */
/* read directly from the EEPROM */
if (w1_reset_select_slave(sl)) {
count = -EIO;
goto out_up;
}
wrbuf[0] = W1_F23_READ_EEPROM;
wrbuf[1] = off & 0xff;
wrbuf[2] = off >> 8;
w1_write_block(sl->master, wrbuf, 3);
w1_read_block(sl->master, buf, count);
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
out_up:
mutex_unlock(&sl->master->bus_mutex);
return count;
}
/**
* Writes to the scratchpad and reads it back for verification.
* Then copies the scratchpad to EEPROM.
* The data must be on one page.
* The master must be locked.
*
* @param sl The slave structure
* @param addr Address for the write
* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
* @param data The data to write
* @return 0=Success -1=failure
*/
static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
struct w1_f23_data *f23 = sl->family_data;
#endif
u8 wrbuf[4];
u8 rdbuf[W1_PAGE_SIZE + 3];
u8 es = (addr + len - 1) & 0x1f;
/* Write the data to the scratchpad */
if (w1_reset_select_slave(sl))
return -1;
wrbuf[0] = W1_F23_WRITE_SCRATCH;
wrbuf[1] = addr & 0xff;
wrbuf[2] = addr >> 8;
w1_write_block(sl->master, wrbuf, 3);
w1_write_block(sl->master, data, len);
/* Read the scratchpad and verify */
if (w1_reset_select_slave(sl))
return -1;
w1_write_8(sl->master, W1_F23_READ_SCRATCH);
w1_read_block(sl->master, rdbuf, len + 3);
/* Compare what was read against the data written */
if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
(rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
return -1;
/* Copy the scratchpad to EEPROM */
if (w1_reset_select_slave(sl))
return -1;
wrbuf[0] = W1_F23_COPY_SCRATCH;
wrbuf[3] = es;
w1_write_block(sl->master, wrbuf, 4);
/* Sleep for 5 ms to wait for the write to complete */
msleep(5);
/* Reset the bus to wake up the EEPROM (this may not be needed) */
w1_reset_bus(sl->master);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
#endif
return 0;
}
static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
int addr, len, idx;
if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
return 0;
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
/* can only write full blocks in cached mode */
if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
(int)off, count);
return -EINVAL;
}
/* make sure the block CRCs are valid */
for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) {
dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off);
return -EINVAL;
}
}
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
mutex_lock(&sl->master->bus_mutex);
/* Can only write data to one page at a time */
idx = 0;
while (idx < count) {
addr = off + idx;
len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
if (len > (count - idx))
len = count - idx;
if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) {
count = -EIO;
goto out_up;
}
idx += len;
}
out_up:
mutex_unlock(&sl->master->bus_mutex);
return count;
}
static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE);
static struct bin_attribute *w1_f23_bin_attributes[] = {
&bin_attr_eeprom,
NULL,
};
static const struct attribute_group w1_f23_group = {
.bin_attrs = w1_f23_bin_attributes,
};
static const struct attribute_group *w1_f23_groups[] = {
&w1_f23_group,
NULL,
};
static int w1_f23_add_slave(struct w1_slave *sl)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
struct w1_f23_data *data;
data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
sl->family_data = data;
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
return 0;
}
static void w1_f23_remove_slave(struct w1_slave *sl)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
kfree(sl->family_data);
sl->family_data = NULL;
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
}
static struct w1_family_ops w1_f23_fops = {
.add_slave = w1_f23_add_slave,
.remove_slave = w1_f23_remove_slave,
.groups = w1_f23_groups,
};
static struct w1_family w1_family_23 = {
.fid = W1_EEPROM_DS2433,
.fops = &w1_f23_fops,
};
module_w1_family(w1_family_23);
MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));
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